Improvement in rotary printing-presses



NIT-ED TATEs PATENT. OFFICE. A

WILLIAM BRAIDWOOD AND HORATIO J. HEWITT, OF NEW YORK, N. Y.

IMPROVEMENT lN ROTARY PRlNTlNG-PRESSES.

Specification forming part of Letters Patent No. 141,314, dated July 29, 1873; application filed April 16, 1873.

To all whom it may concern:

Be it known that we, WILLLIAM BRAID- woon and HORATIO J. HEWITT, both of the city, county, and State of New York, have invented a new and useful Improvement in Printing-Presses; and we do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being had to the accompanying drawing forming part of this specification, in which drawing- Figure 1 represents a longitudinal vertical section of this invention. Fig. 2 is a partial plan or top view of the same. Fig. 3'is a partial side view of the same. Fig. 4 is a detachedface view of our knife. Fig. 5 is a detached section of the air valve and pipe. Fig. 6 is a plan view of one pair of cylinders.

Similar letters indicate corresponding parts.

This invention relates to certain improvements on a printing-press in which both sides of a sheet of paper are printed in succession, the first side being printed by one, and the second by another, set of cylinders. Our present improvement consists, also, in the arrangement of an endless ink-distributing apron, serving to transmit the ink from the fountain to a series of inking-rollers, which bear against the surface of the type-cylinder, and which are mounted in a frame so as to embrace a large portion of the circumference of the type-cylinder; further, in the combination of a continually-advancing offset-sheet with a type-cylinder and an impression-cylinder, in such a manner that the surface of the impression-cylinder is fully protected against being soiled by any impression on that side of the sheet to be printed which faces the impression-cylinder, and at the same time an entirely fresh surface of the offset-sheet is interposed; further, in the combinationof a draw-roller and a turning-roller with the last impression-cylinder, so that the sheet of paper or other material, after having been passed over the drawroller, is turned in over the cutting-table; also, in the arrangement of a stationary cutting-blade on the end of the cutting-table, said blade acting in conjunction with a knife, which is suspended from bell-crank le- I vers, actuated by cams secured to the last type-cylinder in such a manner that, by the action of the knife, the printed sheet is cut in pieces of suitable length. A retaining-pad acts in conjunction with the knife.

In the drawing, the letter A designates a frame which forms the bearings for two impression-cylinders, I I, and two type-cylinders, T T, which are arranged in relation to each other as shown in Fig. l,'the type-cylinder T working in conjunction with the impression-cylinder I, and the type-cylinder T in conjunction with the impression-cylinders I, while the position of the two pairs of cylinders in relation to each other is such that a sheet of paper passed through between them is first printed on one side by the co-operain contact with a series of ink-distributing rollers, 11, which have their bearings in segmental cheek-pieces e secured to the rollerframes B, and which are so-situated that they embrace a large portion of the circumference of the type-cylinder. The apron a is supplied" with ink from a fountain, f, and as said apron moves on the ink spread on its surface is brought in contact with the distributing-rollers d, which transmit it to the type on the type-cylinder. By this arrangement the ink is uniformly distributed over all parts of the type, and perfect inking is obtained.

The cylinders I T and I T are provided with circular bearing-surfaces g, so that, by moving the corresponding cylinders until their circular bearing-surfaces are in contact with each other, the surface of the type-cylinder is brought in the requisite relation to the surface of the impression-cylinder, and the impressions produced are uniform throughout the entire width of the web or sheet passed through between said cylinders.

The web S, which is to receive the impressions, passes down between the two pairs of cylinders I T and I T, in the manner indicated in Fig. 1, and as it passes through between the cylinders I T it receives an impression.

To prevent the impression thus produced on one side of the web from soiling the surface of the impression-cylinder we use an offset-sheet, G, which is taken from a roller, D, whence it passes round the impression-cylinder 1 to a take-up roller, E, the motion of which is so adjusted that it causes the offsetsheet to advance with the same speed with which the impression-cylinder revolves. By this arrangement that portion of the offsetsheet which is in contact with the impressioncylinder 1 is continually changed, and the first impression produced on the web is not liable to become blurred or indistinct.

When the offset-sheet has been taken up entirely by the roller E this roller is interchanged with the roller D, and the same offset-sheet can be used repeatedly until it becomes worn out or soiled.

The web S, after having received the second impression, is carried down over the drawroller F, which acts in conjunction with a turning-roller G, so that the web is prevented from being carried round and round by the impression-cylinder I.

The draw-roller and the turning-roller are geared together with each other, so that they revolve with the same superficial velocity, and they are also geared together with the impression-cylinder I, so that their superficial velocity is very little larger than that of the impression-cylinder, just sufficient to keep the web tight without tearing the same. The draw-roller is provided with a series of grooves to receive cords h, which extend round a roller, 13, so that the end of the web, after having passed through between said draw-roller and the turning-roller G, is caused to turn down upon the cutting-table H. On the end of this cutting-table is secured a stationary cutting-blade, j, the edge of which co-operates with the knife is. This knife is suspended from two bell-crank levers,l m, "which have their fulcrums in pivots a secured in the frame A, and the vertical arms at of said bell-crank levers are pressed down by springs 19 against cam-disks 0 mounted on the shaft of the type-cylinder T. As this cylinder revolves, the ends of the arms on (on which are mounted friction-rollers) drop into cavities on the peripheries of the cam-disks 0, and the knife, being free to follow the action of the springs 12, descends with considerable force, and thereby the web is out. One or more cavities may be made in the camdisks 0, according to the nature of the impression and the size of sheets into which the web is to be cut.

The cutting-edge of our knife is serrated, as shown in Fig. 4, and our experience shows that a knife of this kind is less liable to become dull than a knife with aplain cuttingedge, and that the same, even if dull, will still separate the web at the desired intervals. With the knife 70 is combined a spring-pad, g, which, as the knife descends, presses the web down on the stationary cutting-blade j, and retains the same firmly in position while the knife takes action. As soon as the knife has completed its action the cam-disks. 0 carry the same back into its original position ready for a subsequent action.

Each sheet after having been cut off by the knife is received between two sets of tapes, 1" 1, which extend round rollers s s, and which serve to deliver said sheet to gripers t, which are secured to belts a, stretched around pulleys or drums c, and which are opened and closed at the proper intervals by a mechanism similar to that usually employed on gripers of printing-cylinders.

By the gripers t the sheet is carried under the air chamber or valve L, which is provided with a series of nozzles, to, and which fits closely against a pipe, M, that connects with a reservoir containing air under pressure. In the lower portion of the pipe M are a series of holes, 00, and the valve L is provided with ports y, which communicate with the nozzles w. Said valve can be moved under the air-pipe M, and whenever it is brought in such a position that the holes 00 correspond with the ports y of the valve, jets of air are ejected through the nozzles to.

The valve L is subjected to the action of a lever, a., Fig. 2, and of a spring, I), which has a tendency to force said valve to its closing position. The lever a is actuated by a cam, 0, the motion of which is so timed that the valve L is thrown in its open position at the moment the sheet retained by the gripers t has arrived, in the proper position over the receivingtable N. At that moment the gripers are thrown open, and, as the valve is opened, jets of air are ejected through the nozzles w, and the sheet is thrown down upon the receiving-table, the jets of air act ing on the sheet at or near its back end, while the forward end of said sheet is left to take care of itself.

'By this arrangement we are enabled to discharge the printed sheets from our press in a regular pile, since, if the rear ends of the successive sheets are brought down exactly one above the other, the front ends of said sheets will also come in the required position.

What we claim as new, and desire to secure by Letters Patent,.is-

l. The endless apron a, arranged upon rollers mounted upon the hinged frame B, in combination with the ink-fountain f and a series of inking-rollers, d, which bear directly against the surface of the type-cylinder, substantially as herein described, for the object specified.

2. In combination with a type-cylinder and an impressioncylinder, the oifsetsheet G and interchangeable or reversible rollers D E, substantially as described, for the purpose specified.

3. The draw-roller F, turning-roller G, and impression-roller T, all geared together as described, in combination with the roller i, cords h, and table H, substantially as described, for the purpose specified.

4. The knife K, suspended from the bell-' crank levers Z Z, having arms m m, and operated by cams on the impression-cylinder T,

in combination with each other and with the 

